What is the difference between limited and reasonable assurance?

Limited assurance is expressed negatively, that nothing has come to the practitioner's attention suggesting the information is materially misstated. Reasonable assurance is expressed positively, that the information is fairly presented, and it needs far more testing and costs more. Australia starts with limited assurance and moves to reasonable over time.

Do we have to report Scope 3 in year one?

No. AASB S2 gives first-time reporters relief from disclosing Scope 3 greenhouse gas emissions in their first annual reporting period, and Scope 3 is required from the second year. Taking the relief in year one is normal, but the supplier data work needs to start in year one anyway.

What does an assurance provider actually test in year one?

In year one they test the disclosures inside the ASSA 5010 first-year scope: Scope 1 and Scope 2 emissions, governance disclosures, and specified strategy paragraphs on climate risks and opportunities. The work runs in a predictable order, from understanding your reporting process and your boundary, through sampling source documents and reperforming calculations, to written representations at the end.

Glossary›Assurance, audit evidence and working papers›ASSA 5010

Glossary term

Cluster A · A40

Tier 1 · differentiator

ASSA 5010

Definition

ASSA 5010 sets the timetable for how much of an Australian sustainability report must be assured, and at what level, in each reporting year. In the first year a review covers governance, strategy risks and opportunities, and Scope 1 and Scope 2 emissions. Reviews extend to all disclosures in years two and three. An audit covers everything from year four.

AUASB

· ASSA 5010 paragraph 10 · operative for financial years commencing 1 January 2025 to 30 June 2030

On this page

In practice
What the assurer does with it
Commonly confused with
Timing and relief
Sources
Related terms
Related questions

Cluster

A · Assurance, audit evidence and working papers, 47 terms

In practice

ASSA 5010 is the shortest standard in the regime and the one with the most direct effect on a controller’s workload. It answers one question: what is in scope this year.

The phasing under paragraph 10 runs on each entity’s own reporting years, not on calendar dates. That is the point most often got wrong. A Group 2 entity’s “year one” is its first reporting year, which begins on or after 1 July 2026, so its year four begins on or after 1 July 2029. Group 1’s year one begins on or after 1 January 2025 and its year four on or after 1 January 2028. Group 3 starts from 1 July 2027 and reaches year four from 1 July 2030, which is also the Corporations Act backstop for audit-level assurance over all climate disclosures.

Paragraph 10’s first-year scope is narrower than entities expect, and that narrowness is a trap rather than a relief. The disclosures in scope in year one are governance, strategy covering climate-related risks and opportunities, Scope 1 and Scope 2 greenhouse gas emissions, and any statement by a Group 3 entity that it has no material climate-related risks or opportunities. Everything else in the report is unassured in year one and fully in scope in year two. An entity that builds a defensible file only for the year-one scope has one year to build the rest, on a report it has already published.

Paragraph 11 deals with comparatives and is genuinely helpful. If comparative information was not assured previously, it does not need to be assured now. If prior-year information received limited assurance, the comparative does not need to be lifted to reasonable assurance in a later year. You are not retro-assuring your own history each time the level steps up.

What the assurer does with it

The assurer uses ASSA 5010 to scope the engagement and it appears directly in the engagement letter and in the report. Expect the report to name the reporting year and identify exactly which disclosures were reviewed and which, if any, were audited.

The standard sets a floor, not a ceiling. Paragraph 10 permits the auditor to do more: to audit where only a review is required, or to cover information beyond the mandated subset. Some entities ask for this deliberately in year three to rehearse the year-four audit on a live file rather than discovering the control gaps under a statutory deadline.

What the assurer will not do is treat an out-of-scope disclosure as assured because it sat next to an in-scope one. If your year-one Scope 3 figure appears on the same page as the assured Scope 1 and Scope 2 numbers, the report will say so explicitly, and the practitioner will check that your report presentation does not imply otherwise. Presenting unassured figures so that a reader would take them as assured is the single most common presentation query in a first-year engagement.

Commonly confused with

The AASB S2 reporting reliefs, which are a different phasing on a different axis. AASB S2 phases what you must disclose; ASSA 5010 phases what must be assured. A disclosure can be required and unassured in the same year, and in year one many are.

Timing and relief

The standard is itself time-limited: operative for financial years commencing from 1 January 2025 to 30 June 2030. It expires because after 30 June 2030 the Corporations Act requires audit-level assurance over all climate disclosures and there is no phasing left to describe. ASSA 5010 paragraph 2 sets its own window: “This standard is operative for financial years commencing from 1 January 2025 to 30 June 2030.” After that the phasing it specifies has run its course and the Corporations Act requires reasonable assurance over all climate disclosures in any event, so there is nothing left for the standard to do.